In recent years, there are more smartphone users and handheld tablet device users. Music playing on a traditional mobile device is mostly performed by a same device. Multiple mobile devices collaboratively play a same piece of music, which can increase volume or expand a sound field, improving user experience. However, an audio channel of an audio file (for example, MP3) that is currently widely used by a user is generally mono or binaural (that is, stereo), and a quantity of audio files in a multichannel format (for example, 5.1) is relatively small. If the multiple mobile devices are simply used to play a same audio file, only audio volume is increased and an audio sound field cannot be expanded.
For example, a first solution in the prior art is to use two or more mobile devices to play a mono audio file, where each mobile device plays a same audio signal. For example, referring to FIG. 1, a mobile device 1, a mobile device 2, and a mobile device 3 all play a same mono audio file.
For another example, a second solution in the prior art is to use two or more mobile devices to play a stereo audio file, where some mobile devices play a left audio channel signal of the stereo audio file, and some mobile devices play a right audio channel signal of the stereo audio file. For example, referring to FIG. 2, a mobile device 1 and a mobile device 2 play a left audio channel signal of a same stereo audio file, and a mobile device 3 and a mobile device 4 play a right audio channel signal of the same stereo audio file.
For still another example, a third solution in the prior art is to use multiple mobile devices to play a multichannel audio file (for example, 5.1 channel), where different mobile devices are responsible for playing different audio channel signals. For example, referring to FIG. 3, a mobile device 1 plays a center audio channel signal of a same 5.1-channel audio file, a mobile device 2 plays a left audio channel signal of the same 5.1-channel audio file, a mobile device 3 plays a right audio channel signal of the same 5.1-channel audio file, a mobile device 4 plays a rear-left audio channel signal of the same 5.1-channel audio file, and a mobile device 5 plays a rear-right audio channel signal of the same 5.1-channel audio file.
However, the multiple mobile devices are used to respectively play audio channel signals of the 5.1-channel audio file. Although the (multiple) played audio channel signals are more than the mono signal and the stereo signal, only playing volume is increased and a quantity of the audio channel signals cannot be increased or expanded, that is, an original audio file needs to be multichannel. If the original audio file is stereo or mono, it is impossible to convert, in real time, the original audio file into a multichannel audio file for playing.